The U.S. Supreme Court cleared the way Monday for enforcement of a first-of-its-kind California law that bars psychological counseling aimed at turning gay minors straight.

The justices turned aside a legal challenge brought by supporters of so-called conversion or reparative therapy. Without comment, they let stand an August 2013 appeals court ruling that said the ban covered professional activities that are within the state's authority to regulate and doesn't violate the free speech rights of licensed counselors and patients seeking treatment.

The 9th U.S. Circuit Court of Appeals ruled last year that California lawmakers properly showed that therapies designed to change sexual orientation for those under the age of 18 were outside the scientific mainstream and have been disavowed by most major medical groups as unproven and potentially dangerous.

"The Supreme Court has cement shut any possible opening to allow further psychological child abuse in California," state Sen. Ted Lieu, the law's sponsor, said Monday. "The Court's refusal to accept the appeal of extreme ideological therapists who practice the quackery of gay conversion therapy is a victory for child welfare, science and basic humane principles."

The law says professional therapists and counselors who use treatments designed to eliminate or reduce same-sex attractions in their patients would be engaging in unprofessional conduct and subject to discipline by state licensing boards. It does not cover the actions of pastors and lay counselors who are unlicensed but provide such therapy through church programs.

Liberty Counsel, a Christian legal aid group, had challenged the law, as did other supporters of the therapy. They argue that lawmakers have no scientific proof the therapy does harm.

"I am deeply saddened for the families we represent and for the thousands of children that our professional clients counsel," Liberty Counsel Chairman Mat Staver said in a statement. "The minors we represent do not want to act on same-sex attractions, nor do they want to engage in such behavior."

New Jersey last year became the second U.S. state to ban gay conversion therapy with children and teenagers, and Liberty Counsel also has been fighting that law, which took effect after it was signed by Gov. Chris Christie. The group's litigation counsel, Daniel Schmid, said Monday that the Supreme Court's refusal to consider a challenge to California's law, as opposed to issuing a ruling on the merits, has no bearing on Liberty Counsel's case in New Jersey, which is scheduled to be heard by the 3rd U.S. Circuit Court of Appeals on July 9.

"We hope to get a good ruling out of the 3rd, which will hopefully get us back up to the Supremes," he said.

California's law was supposed to take effect last year, but it has been on hold while a pair of lawsuits seeking to overturn it made their way to the Supreme Court.

Now that the high court has declined to take the case, the state will be able to start enforcing the law after the 9th Circuit lifts an injunction it put into place during the litigation, an action that is expected to come within days, according to Christopher Stoll, a senior staff attorney at the National Center for Lesbian Rights.

Another eight states and the District of Columbia have pending legislation modeled after the California and New Jersey laws, while lawmakers in five other states have refused to pass similar bans. Meanwhile, the Texas Republican Party this month endorsed reparative therapy, adopting policy language recognizing "the legitimacy and efficacy of counseling, which offers reparative therapy and treatment for those patients seeking healing and wholeness from their homosexual lifestyle."